The myriad-minded man, our, and all men's, Shakespeare, has in this piece presented us with a legitimate farce in exactest consonance with the philosophical principles and character of farce, as distinguished from comedy and from entertainments. A proper farce is mainly distinguished from comedy by the licence allowed, and even required, in the fable, in order to produce strange and laughable situations. The story need not be probable, it is enough that it is possible.

On The Comedy of Errors, in Ch. XV - Biographia Literaria (1817)